The field of the invention relates generally to vehicle thermal management, and more specifically, to a method and systems for managing waste heat and supplying heat to various loads in an aircraft.
Aircraft of the type known as “more electric aircraft” are using electric heating for anti-icing. The anti-ice electric loads are high, causing the need for the aircraft electrical system to be oversized in order to accommodate these high electrical loads. This results in excessive weight of the electrical generation and distribution system, excessive engine power extraction, and reduced electrical system efficiency during most of the flight, when anti-ice is not required.
At least some known have used engine bleed air to pressurize the cabin, power the air cycle environmental control system (ECS), and heat the leading edges of the wings and tail to prevent ice formation. Aircraft manufacturers are, moving toward more electric power and away from hydraulic and bleed air. In some cases, bleed air is eliminated, entirely, with these functions being replaced by electrically powered components. The more electric aircraft provides cabin air via an electric motor-driven compressor. A vapor cycle ECS provides, cabin cooling as needed for passenger and crew comfort. The anti-ice functions are performed by electric heaters. These heaters consume a large portion of the total aircraft electrical power, even though they are used for only a small portion of a typical flight. The anti-ice electrical power requirements are a major factor in sizing of the aircraft generators, adding considerable weight to the electrical generating and distribution system. The generators are oversized for the loads encountered during the major portion of the flight and operate less efficiently than they would if anti-ice were provided by another means.